View Compilation Error

0_0_15210439_6345.cpp: In function 'long long int C(int, int)':
0_0_15210439_6345.cpp:50:63: error: 'get_mod' was not declared in this scope
  for(int i = 1; i <= m; i++) ans = ans * get_mod(i, MOD-2, MOD) % MOD; 
                                                               ^